Differential lock for tractors



Apyil 26, 1927.

G. C. ABBE DIFFERENTIAL LOCK FOR TRACTORS Filed July 18. 1925 Patented Apr. 26, 1927.

, Lezama enonenennn, or KENNETT SQUARE, rENNsYLvANrA, AssIGNoRTo AnnnrcAN ,n.noADi MACHINERY COMPANY, INC., ortKENNETT, saUARarENNsYLvANrA; A

, CORPORATION OF DELAWARE..

` DIFFERENTIAL Loox roRfkTRACToRs.

Application fue@ Julyis, 192i. serial No. 44,500.

v .My invention relates to a: differential lock for tractors'and. other motor operated vehicles. As is'well known,y the provision of. ysom form ofv differential is necessary iny vehicles,

" suchV as tractorsradapted to be self-propelled7 vtof-rotatie* more slowly than thev other when y the vehicle'is turned, as 1n going aroundcorin lorder to enable one of the driven wheels ners or turning around.

f @The provision of a differential,howeverv v necessary to Ameet certain conditions, is frel--quently a source of `disadvantage where the:

tractor is-operating off a road, or in 'road 'vb'uildingg or repair work in wet weather,v since if one of'the'driven wheels 'comes upon `a slippery spot-'and'loses traction it will rotate freely due to the action of the diffe-rential, vand the other wheel will `receive no "pvower Asla'result, r`the tractor'pwill notA move. A.

Io meetlsuchwconditions there has beenl #proposed a-variety of devices for lockingy thedifferential in order toV insure the delivery of power to both wheels irrespective of whether or not one of them loses traction. Such devices as have been proposed have been open to a number of serious objections which have rendered them substantially im. practical and chief among which is thaty 'when the di'erentia'l is locked, the differential notonly does not function when one of the wheels loses traction, but it does not function under any circumstances, as in turning, with the result that damage to the-*differential is likely to occur unless the lock be used only'in cases where one of the wheels loses traction. Such is a serious disadvantage7 especially when a tractor is working y under adverse conditions where one or the other of the driven wheels frequently loses traction and at the same time the duty of the tractor requires frequent turning. f

Now it is the object of my invention to provide a differential lock extremely simple inconstruction, which will effectively lock the dierential when a vdriven wheel loses traction, and which at the same time will permit operation of the differential to `permit either one of the driven wheels to rotate more slowly than the other when the tractor is turned. Having now indicated, in a general way, the nature and purpose of my invention, I

- ydrawing in.` whichf lthere isillustratede` a yferred embodiment,`- and in.which"-.y

of, with 'refer-ence to thev.accompa'nying`` Fig. 1 is a plan view, partlyinsectionliof y the rear portion of'a tractor embodying my invention. i Fig. l2 is a sectional view,jon a largeiscale, showing a detail ofmy, invention.l

a represents the frame of theftractor upon which is mounted apower unit ib, which, for example, may be'v afFordsomtractor-from which the wheelshave been-removed. Secured `to the side. members ofthe .frame a adjacent the rear end are a pair.'` offbrackets c to which is clamped therearz'axlehousing' d 1 whichv,.c'arries audifferen- .ztial and live axles.

of the power unit,A

Bearings e are formed in the brackets'and -serve to supporta rotatable axle ff. which `extends in ,parallelism)with the llive axles of `the power unit-.LLOn the. axle :flare supported a pair v of Y wheels 'g5 gf,,:th'e fwheelgfnbeing pinned to the axle f by means of a pin h,

while the wheel g is free to turn on the axle, being retained thereon by a collare'.

"To the hubs of the wheels are secured sprockets j connected by means of chains 7c to sprockets Z secured to the ends of the live axles of the power unit. The outer end of the hub of the wheel g is formed tocompose one member m of a frictionl clutch of any type but preferably as shown, while vthe other member n is splined, keyed, or otherwise secured on the end of axle f, being adjustable relative to the member m by means of a bolt o threaded into the end of the axle.

It will now be apparent that thel wheels members m and fn, to be separated. The

wheel g will be driven and will rotate axle f, while the wheel g will be driven independently of the :rotation of axle f; Thus,' the wheels q and g being independent, the

differentialof the power unit will-be free to act. v

If now one of tion and it be desired to lock the 'differ- Vential, itis only necessaryto draw'member m up to member n by means of screw o7 thus frictionally connecting wheel g to axle f and causing thedrive on either wheel g the wheels g, gf loses traci members m and n vto slip relative to each other, thus permitting the differential to act fiand avoidingpany possibility of damage.

VI-Iavingnow fully described mylinvention,

`what Iclavim' and desire to protect by Letters Patent is: l

l. In' a tractor, 'in combination, a pair of wheels, a one piece axle extending through the hubs of both wheels, one of which is rotatably mounted on saidaxle and the other of which is'fixedly mounted thereon, means for driving said-wheels including a Vdifferential gearing havinga two part shaft, driving connections between the axle and one partV of the shaft, 'driving connections between the othervpart of'the'shaft and the i wheelrotatably mounted on the axle,l and means adapted to afford a connectionV between said axle andv said wheel rotatably mounted thereon. Y

'2. In a tractor, in combination, a power unit including a differential gearing having a two part shaft, a rear axle, a pair of wheels one of which is rotatably mounted on said .ber lixedly mounted on axle and the yother of which is lixedly mounted thereon, driving connections betweeneach wheel and one of the parts of the shaft of said differential, a friction member ixedly mounted `on said axle, a'complementary friction f member mounted on said 5 rotatably mounted wheel, and means for adjusting one of said members in relation to the other Lio` whereby a desired degree of frictional engagement between said rotatably mounted n 3'. In a tractor, in combinatioma power wheel and said axle may be effected.

unit including` la differential gearing having a two part shaft, a rear axle, a ypair of wheels .one of which is rotatably .mounted on said axle and the other ofwhich is ixedly mounted thereon, drivingv connection be-zk tween each wheel and one of the'parts of;

the shaft of said differential, a friction mem-L n said rotatably mounted wheel, a complementary friction member slidably mounted on said axlev'adjacent said lirst mentioned member, and

means lengaging' said last mentioned member andvsaid axle for 'adjusting saidmemvber relative to said first mentioned-member,

whereby a desire-d degree of Hfrictional engagement between said members maybe effected.

In testimony ofiwhich inventiomI have hereunto set my hand, at Kennett Square, Penna., on this 3rd day of July, 1925;

GEORGE o. ABBE. 

